Lamp base



FIG. 1 is a front elevation of a lamp base showing my new design;

FIG. 2 is a side elevation; and

FIG. 3 is a section taken on lines 3--3 of FIG. 1, looking in the direction of the arrows.

The shade is shown in broken lines for illustrative purposes only. 

The ornamental design for a lamp base, as shown and described. 